You know, I never really thought about it before.
Consider a typical roulette wheel. There are 38 numbers on a roulette wheel (0, 00, 1-36) meaning the odds are 1 in 37 to win (roughly 2.7%, which means the 'house' has a [roughly]97.3% chance to win). To win 100% of the time, one would have to place a bet on all 38 numbers. This, while possible, would actually mean losing money because roulette pays out at 35:1 if you bet on a single number (if you bet $1 on a winning number, you now have $35).
It similarly makes no sense to bet on 35 numbers because you would still, statistically, end up losing money and only ever 'break even' whenever you win.
So to turn a profit, the most numbers one can bet on would be 34 which is, roughly, 89% percent of the board. What that means is that placing $1 on 34 individual numbers would earn you a whopping $2 (you 'lose' on 33 tiles [$33] but 'win' on 1 number [$35]. 35-33=2).
Now, of course, there is a (roughly) 11% chance that you'll lose all $34.
If you bet $1 on one number for 38 games in a row you would, statistically, win once with a payout of $35. However, you would lose $1 on 37 of those bets at a cost of $37. Meaning overall, you have a net loss of $2 ($37-$35=$2).
Now, if one were to bet $1 each on 34 numbers for 38 games in a row one would, statistically, win 34 of those games at a rate of $2 a win. Meaning overall winnings of $68. When you lose, however, you lose hard and you would lose $34 4 times which amounts to $136 (34*4=136). Subtracting our winnings of $68, we have an overall loss of $68 (136-68=68).
It seems like its actually 'safer' to bet on just one number consistently. At least, you'll bleed your monies out a lot slower.
The odds of winning in Ghoulette are 1:11 (or, roughly, 9%). The payout is 10:1 thus to actually win something, one can only place stuff on 9 numbers (75% of available numbers). Let us assume the bet is 1gp on each individual number with a payout of 10gp (1pp) on a winning number.
So, if one plays for 12 rounds, and one bets 1gp on one individual number, one is expected to win once for 10gp total. However, one would lose 11 other times at a rate of 1gp a round meaning a net loss of 1gp.
Now, if one plays for 12 rounds and bets 1gp on 9 individual numbers, one is expected to win nine times for 9gp in profit. However, one would lose 9gp 3 times for total loses of 27gp. Subtracting from our winnings, that's a net loss of 18gp.
So in either case, its smarter to just bet on one number.
See kids, math isn't useless XP